The Network Solver (Experimental)

Macro Variable _OROPTMODEL_

The OPTMODEL procedure always creates and initializes a SAS macro variable called _OROPTMODEL_, which contains a character string. After each PROC OROPTMODEL run, you can examine this macro variable by specifying %put &_OROPTMODEL_; and check the execution of the most recently invoked solver from the value of the macro variable. You can also extract each keyword and value pair to obtain details about the solution even if you do not specify an output destination in the OUT= option.

After the solver is called, the various keywords in the variable are interpreted as follows:

STATUS

indicates the solver status at termination. It can take one of the following values:

OK: The solver terminated normally.
SYNTAX_ERROR: The use of syntax is incorrect.
DATA_ERROR: The input data is inconsistent.
OUT_OF_MEMORY: Insufficient memory was allocated to the procedure.
IO_ERROR: A problem in reading or writing of data has occurred.
SEMANTIC_ERROR: An evaluation error, such as an invalid operand type, has occurred.
ERROR: The status cannot be classified into any of the preceding categories.

SOLUTION_STATUS

indicates the solution status at termination. It can take one of the following values:

ABORT_NOSOL: The solver was stopped by the user and did not find a solution.
ABORT_SOL: The solver was stopped by the user but still found a solution.
BAD_PROBLEM_TYPE: The problem type is not supported by the solver.
CONDITIONAL_OPTIMAL: The optimality of the solution cannot be proven.
ERROR: The algorithm encountered an error.
FAIL_NOSOL: The solver stopped due to errors and did not find a solution.
FAIL_SOL: The solver stopped due to errors but still found a solution.
FAILED: The solver failed to converge, possibly due to numerical issues.
HEURISTIC_NOSOL: The solver used only heuristics and did not find a solution.
HEURISTIC_SOL: The solver used only heuristics and found a solution.
INFEASIBLE: The problem is infeasible.
INFEASIBLE_OR_UNBOUNDED: The problem is infeasible or unbounded.
INTERRUPTED: The solver was interrupted by the system or the user before completing its work.
ITERATION_LIMIT_REACHED: The solver reached the maximum number of iterations that is specified in the MAXITER= option.
NODE_LIM_NOSOL: The solver reached the maximum number of nodes specified in the MAXNODES= option and did not find a solution.
NODE_LIM_SOL: The solver reached the maximum number of nodes specified in the MAXNODES= option and found a solution.
OK: The algorithm terminated normally.
OPTIMAL: The solution is optimal.
OPTIMAL_AGAP: The solution is optimal within the absolute gap that is specified in the ABSOBJGAP= option.
OPTIMAL_COND: The solution is optimal, but some infeasibilities (primal, bound, or integer) exceed tolerances because of scaling.
OPTIMAL_RGAP: The solution is optimal within the relative gap that is specified in the RELOBJGAP= option.
OUTMEM_NOSOL: The solver ran out of memory and either did not find a solution or failed to output the solution due to insufficient memory.
OUTMEM_SOL: The solver ran out of memory but still found a solution.
SOLUTION_LIM: The solver reached the maximum number of solutions specified in the MAXCLIQUES=, MAXCYCLES=, or MAXSOLS= option.
TARGET: The solution is not worse than the target that is specified in the TARGET= option.
TIME_LIM_NOSOL: The solver reached the execution time limit specified in the MAXTIME= option and did not find a solution.
TIME_LIM_SOL: The solver reached the execution time limit specified in the MAXTIME= option and found a solution.
TIME_LIMIT_REACHED: The solver reached its execution time limit.
UNBOUNDED: The problem is unbounded.

PROBLEM_TYPE

indicates the type of problem solved. It can take one of the following values:

BICONCOMP: Biconnected components
CLIQUE: Maximal cliques
CONCOMP: Connected components
CYCLE: Cycle detection
LAP: Linear assignment (matching)
MCF: Minimum-cost network flow
MINCUT: Minimum cut
MST: Minimum spanning tree
SHORTPATH: Shortest path
TRANSCL: Transitive closure
TSP: Traveling salesman
NONE: This value is used when you do not specify an algorithm to run.

OBJECTIVE

indicates the objective value that is obtained by the solver at termination. For problem classes that do not have an explicit objective, such as cycle, the value of this keyword within the _OROPTMODEL_ macro variable is missing (.).

PRESOLVE_TIME

indicates the real time taken for preprocessing (seconds).

SOLUTION_TIME

indicates the real time taken by the interior point algorithm to perform iterations for solving the problem (seconds).

The following keywords within the _OROPTMODEL_ macro variable appear only with certain algorithms. The keywords convey information about the number of solutions each algorithm found:

NUM_ARTICULATION_POINTS: indicates the number of articulation points found. This term appears only for biconnected components.
NUM_CLIQUES: indicates the number of cliques found. This term appears only for clique.
NUM_COMPONENTS: indicates the number of components that match the definitions of the corresponding problem class. This term appears only for connected components and biconnected components.
NUM_CYCLES: indicates the number of cycles found that satisfy the criteria you provide. This term appears only for cycles.